Time-resolved photoluminescence of barium titanate ultrafine powders

Abstract

Time-resolved photoluminescence ͑PL͒ near 540 nm, taken from barium titanate ͑BaTiO 3 ͒ ultrafine powders of ϳ80, 90, and 110 nm in size, was measured at 11 K. Two-exponential functions were found to fit the decay curves well, and the decay lifetimes were composed of one short, about 10 ns, and one long, about 200 ns, time constants, respectively. Results also indicate that the PL peaks show a small blueshift with decreasing BaTiO 3 particle size. The decay process consists of the recombination of self-trapped excitons ͑long lifetime decay͒ and of the electrons in the surface states with the holes in the valence band ͑short lifetime decay͒. The short lifetime component makes comparable contribution to the decay intensity of PL with the long lifetime one.

Luminescent Properties of Surface Functionalized BaTiO3 Embedded in Poly(methyl methacrylate)

“…All spectra were fitted using multiple Gaussian peaks. The bandgap emission at 3.0 eV (0.28 eV FWHM) is in good agreement with previously reported results [ 12 ]. The complex band at ~2.5 eV is composed of three peaks at 2.7 (0.27 eV FWHM), 2.5 (0.27 eV FWHM), and 2.2 eV (0.28 eV FWHM).…”

“…Lu et al . [ 12 ] reported the broad visible emission intensity to decrease with increasing temperature and quench completely at 74 K. Our samples show no significant relationship between temperature and PL intensity of the peaks about 2.5 eV. In both BTO50 and BTO100, a very slight blue shift of 0.01 eV of the bandgap is observed at 8 K and the 2.2 eV component of the complex peak blue shifts to 2.3 eV.…”

“…It was found that many radiative transitions in BTO manifest themselves only in nanoscale crystals. For example, multiple bands in the visible part of the spectrum were observed in very thin films and nanoparticles (NPs) [ 10 – 12 ]. In the work by Zhang et al .…”

Photoluminescence from Boron‐Doped Titanium Nitride Nanocomposite Thin Films Prepared by the Magnetron Sputtering Method

“…The emitted light from the samples was collected by a 25‐cm focal‐length double‐monochromator (Oriel 77225, Irvine, CA) and detected by a thermoelectrically cooled photomultiplier tube (PMT) (Hamamatsu R636‐10, Shizuoka, Japan). The details of the PL measurement have been published elsewhere 11 …”

Hydrothermal synthesis and photoluminescence properties of BaZr1−xTixO3 hollow nanospheres

“…Recently, much attention has been paid to perovskite hollow nanostructures because of their novel functionalities [2]. Perovskite oxides of group IV elements with oxygen vacancies, including nanopowders and thin films of SrTiO 3 , BaTiO 3 , BaZrO 3 and SrZrO 3 exhibited strong defect-induced violet, blue or green light emission at room temperature [3][4][5][6][7][8]. As is well-known, nanomaterials were abundant in defects.…”